Multi-variate stepwise discriminant analysis research affecting portal hypertension’s grade factors of liver function

1994 ◽  
Vol 14 (1) ◽  
pp. 56-60
Author(s):  
Peng Zhi-hai ◽  
Qin Xiu-fu ◽  
Zhao Ye-min

1977 ◽  
Vol 23 (4) ◽  
pp. 627-630 ◽  
Author(s):  
Paul Phillip Sher

Abstract I evaluated the diagnostic value of routinely ordered liver-function tests in 175 biopsy-proven cases of hepatic disease by use of stepwise discriminant analysis. The tests studied—total and "direct" bilirubin, alkaline phosphatase, lactate dehydrogenase, and aspartate aminotrans-ferase—correctly classified 45-73% of cases, depending on the homogeneity of the diagnostic groups. Aspartate aminotransferase and alkaline phosphatase were the best discriminators. When all tests were used in the most ho-mogeneous groups (tumors, cirrhosis, and hepatitis), there was a stepwise improvement in diagnostic accuracy from 51 to 73%.



2015 ◽  
Vol 1 (311) ◽  
Author(s):  
Katarzyna Stąpor

Discriminant Analysis can best be defined as a technique which allows the classification of an individual into several dictinctive populations on the basis of a set of measurements. Stepwise discriminant analysis (SDA) is concerned with selecting the most important variables whilst retaining the highest discrimination power possible. The process of selecting a smaller number of variables is often necessary for a variety number of reasons. In the existing statistical software packages SDA is based on the classic feature selection methods. Many problems with such stepwise procedures have been identified. In this work the new method based on the metaheuristic strategy tabu search will be presented together with the experimental results conducted on the selected benchmark datasets. The results are promising.



2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Nathalie André ◽  
Claude Ferrand ◽  
Cédric Albinet ◽  
Michel Audiffren

Background. Although a number of studies have examined sociodemographic, psychosocial, and environmental determinants of the level of physical activity (PA) for older people, little attention has been paid to the predictive power of cognitive strategies for independently living older adults. However, cognitive strategies have recently been considered to be critical in the management of day-to-day living. Methods. Data were collected from 243 men and women aged 55 years and older living in France using face-to-face interviews between 2011 and 2013. Results. A stepwise discriminant analysis selected five predictor variables (age, perceived health status, barriers’ self-efficacy, internal memory, and attentional control strategies) of the level of PA. The function showed that the rate of correct prediction was 73% for the level of PA. The calculated discriminant function based on the five predictor variables is useful for detecting individuals at high risk of lapses once engaged in regular PA. Conclusions. This study highlighted the need to consider cognitive functions as a determinant of the level of PA and, more specifically, those cognitive functions related to executive functions (internal memory and attentional control), to facilitate the maintenance of regular PA. These results are discussed in relation to successful aging.



Data Mining ◽  
2013 ◽  
pp. 92-106
Author(s):  
Harleen Kaur ◽  
Ritu Chauhan ◽  
M. Alam

With the continuous availability of massive experimental medical data has given impetus to a large effort in developing mathematical, statistical and computational intelligent techniques to infer models from medical databases. Feature selection has been an active research area in pattern recognition, statistics, and data mining communities. However, there have been relatively few studies on preprocessing data used as input for data mining systems in medical data. In this chapter, the authors focus on several feature selection methods as to their effectiveness in preprocessing input medical data. They evaluate several feature selection algorithms such as Mutual Information Feature Selection (MIFS), Fast Correlation-Based Filter (FCBF) and Stepwise Discriminant Analysis (STEPDISC) with machine learning algorithm naive Bayesian and Linear Discriminant analysis techniques. The experimental analysis of feature selection technique in medical databases has enable the authors to find small number of informative features leading to potential improvement in medical diagnosis by reducing the size of data set, eliminating irrelevant features, and decreasing the processing time.



Author(s):  
Elizabeth Oddone-Paolucci ◽  
Claudio Violato ◽  
Chris Wilkes


1996 ◽  
Vol 22 (3) ◽  
Author(s):  
T. L. Nell ◽  
L. Kamfer ◽  
R. P. Van Der Merwe ◽  
D. J. L. Venter

The personality profile of successful prison warders. In an attempt to develop a personality profile for successful prison warders, scores on CattelFs 16-PF (SA92-form) were obtained from 361 warders employed by the South African Department of Correctional Services. Independent criterion information (tempo of promotion) was also obtained and used as indicator of job success. Using Hotelling's T2, it was found that the first order factor profiles of successful and unsuccessful warders differed significantly. There was no difference in their second order profiles. By means of stepwise discriminant analysis with personality as independent and success (expressed as a dichotomy) as the dependant variable, four first order factors were identified and formulae derived which predicted 14,8 better than chance whether a warder would be correctly classified as successful or not on the dichotomous success criterion. Opsomming In 'n poging om 'n persoonlikheidsprofiel vir suksesvolle bewakingsdienspersoneel saam te stel, is response op Cattell se 16-PF (SA92-vorm) vanaf 361 bewakingsdienspersoneellede werksaam by die Suid-Afrikaanse Departement van Korrektiewe Dienste, verkry. Inligting in terme van onafhanklike kriterium (tempo van bevordering) is ook verkry en gebruik as aanduiding van werksukses. Deur die gebruik van Hotelling se T2 is bepaal dat die ecrsteorde profiele van suksesvolle en onsuksesvolle bewakingsdienslede beduidend van mekaar verskil. Daar is geen beduidende verskil ten opsigte van die tweedeorde profiele gevind nie. Deur middel van stapsgewyse diskriminantontleding, met persoonlikheid as onafhanklike en sukses (uitgedruk as 'n digotomie) as afhanklike veranderlike, is vier eersteorde faktore geidentifiseer en formules saamgestel wat 14,8 beter as toeval kan voorspel of "n persoon suksesvol of onsuksesvol volgens die digotomiese sukseskriterium sal wees.



1996 ◽  
Vol 11 (S2) ◽  
pp. S35-S35
Author(s):  
Anthony Ciccone ◽  
Carol Irving ◽  
Robert F. Lavery ◽  
Bartholomew J. Tortella

Purpose: The prevalence of asthma in the pediatric population is approximately 9% and the incidence of acute exacerbation in this population has been increasing. The purpose of this study was to determine if there has been a change in the pre-hospital presentation and treatment of pediatric asthma.Methods: This observational study was a retrospective consecutive case series comparing pediatric (#18 yrs) asthmatics treated and transported by an inner city EMS system over two years. (1987, 1992). Data collected included patient demographics, prehospital treatment, and evaluated diagnostic criteria used by paramedics to initiate treatment. Students t test was performed for continuous data and contingency analysis (chisquare) for non-continuous data. A Wilks stepwise discriminant analysis was performed on 1987 and 1992 data to evaluate diagnostic factors.Results: There were 407 transports in 1987 and 652 in 1992, representing a 60% increase. 237(56%) of patients received advanced life support (ALS) in 1987 and 344(53%) in 1992. Mean age of ALS patients in 1987 was 10.25 (±5.3) and was 8.03 (±2.8) in 1992 (p <0.001). Albuterol inhalation supplanted epinephrine (1987-205, 1992-1) and aminophylline (1987-15, 1992-1) as the treatment for asthma in our service system. The discriminant analysis revealed that in 1987, paramedics treatment decision making was influenced by age, cough, cold, and/or fever, home medications, accessory muscles, absence of wheezing, and normal respiratory rate. This changed in 1992 where only the presence or absence of wheezing and accessory muscle-use to be highly correlated with treatment decisions.



1982 ◽  
Vol 45 (3) ◽  
pp. 229-233 ◽  
Author(s):  
NORMAN J. STERN

Pyrolysis gas-liquid chromatography (PGLC) and stepwise discriminant analysis (SDA) were ineffective when used to differentiate selected genera, species and strains of foodborne microorganisms. Each of 18 individual bacterial strains analyzed was grown, harvested and subjected to PGLC analysis. The resulting pyrolysis products were separated on a high resolution capillary column and the elution patterns (pyrograms) were subjected to stepwise discriminant analysis of 26 (a–z) characteristic peaks. Classification with the combination of PGLC and SDA was 87% accurate for gram-negative strains of bacteria and 94% accurate for gram-positive strains of bacteria. PGLC-stepwise discriminant· analysis correctly discriminated 80% of the bacterial strains according to the known gram-stain reactions. Only 63% were correctly classified to the genus level when all samples were compared. These findings point out the weak points for this method of bacterial analysis.



1992 ◽  
Vol 75 (3) ◽  
pp. 537-542 ◽  
Author(s):  
R Mateo Castro ◽  
M Jiménez Escamilla ◽  
F Bosch Reig

Abstract The color of 7 types of Spanish unifloral honey from rosemary, orange blossom, lavender, eucalyptus, sunflower, heather, and honeydew was Investigated for Its potential use as a characterization parameter. Colors were estimated by visual comparison with a Lovlbond 1000 Instrument, the readings of which were transformed Into Pfund units. As an alternative method, the transmittances of liquid samples at selected wavelengths were measured, trlstlmulus values were calculated, and chromatic coordinates In the CIE-1931 (x,y,L) and CIE-1976 (L*a*b*) color spaces were determined. The correlation coefficient between x and the Pfund grading was 0.958, but visual comparisons proved to be less objective and precise than CIE parameters; yet, analysis by visual comparison can be used by unskilled dealers and beekeepers because of Its great simplicity. A stepwise discriminant analysis revealed that CIE-1976 (L*a*b*) coordinates yield an overall proportion of accurately classified samples slightly better than that afforded by CIE-1931 coordinates (76 vs 71%). However, rosemary and lavender honeys were more accurately classed by using the CIE-1931 system. The results show that color determinations make a useful tool for helping to classify honeys.



Sign in / Sign up

Export Citation Format

Share Document